Semiconductor apparatus and method of producing the same

Abstract

In a method of producing a semiconductor apparatus, which method includes a trench forming step of forming a trench in a silicon substrate and an inner wall oxidizing step of forming an oxide film on an inner wall of the trench; the inner wall oxidizing step being performed by wet oxidization with a low concentration of moisture mixed in oxygen to form the oxide film so that a stress caused between the oxide film and the silicon substrate is not greater than 3.5×10 9 (dyne/cm 2 ) and a radius at a corner of the trench is 8 nm or more.

1 . A method of producing a semiconductor apparatus, comprising: 
 a trench forming step of forming a trench in a silicon substrate; and    an inner wall oxidizing step of forming an oxide film on an inner wall of said trench;    said inner wall oxidizing step being performed by wet oxidization with a low concentration of moisture mixed in oxygen to form said oxide film so that a stress caused between said oxide film and said silicon substrate is not greater than 3.5×10 9  (dyne/cm 2 ) and a radius at a corner of said trench is 8 nm or more.    
   
   
       2 . A method as claimed in  claim 1 , wherein the concentration of moisture is not greater than 10% and is not smaller than 0.01% at an oxidization temperature of 1100° C.  
   
   
       3 . A method as claimed in  claim 1 , wherein the concentration of moisture is not greater than 2% and is not smaller than 0.01% at an oxidization temperature of 1000° C.  
   
   
       4 . A method as claimed in  claim 1 , wherein the concentration of moisture is not greater than 1% and is not smaller than 0.01% at an oxidization temperature of 950° C.  
   
   
       5 . A method as claimed in  claim 1 , wherein the concentration of moisture has an upper limit given by a curve containing a point of 10% at an oxidization temperature of 1100° C. and a lower limit of 0.01%.  
   
   
       6 . A semiconductor apparatus comprising a silicon substrate provided with a trench having a rounded corner with a radius of 8 nm or more and an oxide film formed on an inner wall of said trench and deposited by wet oxidization at a moisture concentration between an upper limit represented given by a curve containing a point of 10% at an oxidization temperature of 1100° C. and a lower limit of 0.01%.